When a fecale deposit is made into a toilet and the resulting pile sticks out of the water and begins to emit a foul aroma so another layer of toilet paper is put over top to hopefully somewhat decrease the smell. Then you eliminate solid waste on the new layer and are forced to repeat. This is used by people who do not want to waste water, or people who hate the butt spray from a seated courtesy flush.

My thighs were too weak to hover for the flush to be over after a long night of tequila and tacos. So I just cooked up a family sized portion of Portuguese lasagna for the whole second floor of the dorm.